Joe Biden proposed re-instating the assault weapon ban before this happened. Seems like a good idea in a country so saturated with gun violence: since 1981 there have been 47 incidents of mass shootings. There have been five recent shootings of Presidents: Truman, Kennedy, Ford (2), Reagan. It's very American!
Campaigning in 1912 as an independent, Theodore Roosevelt told his crowd he had been shot en route,but nevertheless completed his ninety minute speech. His life was spared by a heavy overcoat, metal eyeglass case, and a folded fifty-page speech text. Slowed down, the .38 Colt handgun bullet shot from close range still penetrated the skin of his chest on a direct path to his heart. Tough monkey, err, moose. Roosevelt lost the ensuing election.
In this particular case, the father purchased an assault-style rifle about six months before his 20 year old son, an unpopular registered Republican, attempted to off the would-be Boss of Bosses. The shooter was a member of a local gun club, but failed to make his high-school rifle team. Notoriously inaccurate, the weapon failed the emotionally unstable assassin at 443 feet. His moment to make history was quickly ended by Secret Service snipers who did not miss.